The present invention relates to an anterior segment three-dimensional image processing apparatus, and an anterior segment three-dimensional image processing method.
In recent years, an optical coherence tomography (OCT) apparatus for photographing a tomographic image of an anterior segment of an eyeball of a subject (subject's eye) by means of optical coherence tomography (hereinafter “anterior segment OCT”) has been provided as an inspection apparatus used for ophthalmic examination.
Specifically, the anterior segment OCT has come to be used, for example, in glaucoma clinics, largely for angle analysis in the narrow angle eye, mainly including primary closed angle diseases and primary closed angle glaucoma together with the suspected (for example, see “Application to glaucoma of anterior segment OCT: Present” written by Koichi Mishima, new ophthalmology Vol. 28 No. 6 P. 763˜768 (issue June 2011)).
Generally, in the anterior segment OCT, one-dimensional scanning by a measurement light is performed on the subject's eye to acquire a two-dimensional tomographic image of one slice plane (B-scan). Further, the two-dimensional tomographic image is repeatedly acquired while shifting a scanning position of the measurement light (in other words, while changing the slice plane) on the subject's eye (C-scan) to obtain an anterior segment three-dimensional image.
As a method of scanning, there is, for example, a method called raster scan, as shown in FIG. 4A. In the raster scan, one-dimensional scanning (B-scan) along a scanning line extending in a horizontal direction is repeated while the scanning position is shifted in a vertical direction (C-scan), and thereby it is possible to obtain a two-dimensional tomographic image along each scan line, as shown in FIG. 4B.
There is also, for example, a method called radial scan, as shown in FIG. 5A. According to the radial scan, one-dimensional scanning (B-scan) along the scanning line extending in a radial direction is repeated while the scanning position is shifted in a circumferential direction (C-scan), and thereby it is possible to obtain a two-dimensional tomographic image along each scan line, as shown in FIG. 5B.
In a conventional anterior segment three-dimensional image processing apparatus, an operator inputs a scleral spur position (SS position) by pointing in a two-dimensional tomographic image of the slice plane obtained as above. Thereby, it was made possible to display an angle portion (portion where a corneal posterior surface and an iris anterior surface are in contact with each other) that is closed beyond the SS position on a chart as an iridotrabecular contact (ITC).